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Unlimited data SIMs: The Essential Guide

With so many SIM plans available right now, it can be difficult to choose between them.

One of the hardest things is figuring out how much data you’ll need. But don’t worry, we’re here to help! In this guide, we explain what unlimited data is, the pros and cons of unlimited data SIMs, and how to decide if it’s right for you.

What is unlimited data?

What are the pros of unlimited data SIMs?

What are the cons of unlimited data SIMs?

Do you need an unlimited data SIM?


Unlimited data bundles available with Asda mobile

What is unlimited data?

Mobile data gives you internet access without a Wi-Fi connection. Devices can use 4G or 5G to get online, now that the 3G shutdown is in progress with networks across the UK.

But the best part is that unlimited data SIMs don’t cap your data allowance - anywhere you need to access the internet, you can!

What are the pros of unlimited data SIMs?

If you use a lot of data each month - either because you don’t have Wi-Fi access or are frequently on the go - then an unlimited data SIM could be your answer.

Some benefits of using unlimited data SIMs include:

  • Worry-free streaming: Bored on public transport? Travel often? Having unlimited data means you can stream as much as you like, from movies on the move to online classes in your spare time.
  • Limitless use: Downloading, updating and, above all, using apps doesn’t cost any extra thanks to unlimited data.
  • Improved connectivity: Zoom, FaceTime, or Skype your loved ones without worrying about how long your conversations last with unlimited data!
  • Money saving on utilities:Opting for an unlimited data SIM means you may wish to bypass installing Wi-Fi at home. A good alternative would be to use your phone as a hotspot for all other household devices. This can drain your charge, though, so weigh up the other pros and cons before making a final decision.
  • Speed: Unlimited data SIMs usually offer faster speeds - sometimes they’re even quicker than Wi-Fi! If you notice your device struggling when connected to a router, switch to unlimited data for hassle-free internet speeds 

What are the cons of unlimited data SIMs?

Of course, there are some potential drawbacks to unlimited data SIMs, including:

  • Cost:Unlimited data SIMs are more expensive than plans with speed caps. You’ll need to factor this into your monthly mobile budget before buying.
  • Waste: If you live in an area with poor Wi-Fi or are on the move a lot, unlimited data SIMs could be your solution. However, if you have a secure connection for most of the day, you could be wasting more data than you actually use!
  • Fair usage limits: ‘Subject to fair use’ - a common caveat of some mobile plans. While ‘unlimited’ does imply unrestricted use, certain plans may have restrictions, so be sure to look out for these. For example, your unlimited data SIM may not be able to support multiple devices, or your internet connection may be restricted after a certain period of use. Always double-check the terms and conditions before committing to any mobile plan, especially if you want unlimited data.
  • Speed caps: Regardless of whether or not you can connect to 4G or 5G, not all unlimited data SIMs provide the same speed - even if they’re with the same provider! To avoid potentially being capped, always double-check your plan’s T&Cs.

Do you need an unlimited data SIM?

If you’re considering an unlimited data SIM, start by asking yourself the following questions:

  • Do you spend a lot of time off Wi-Fi - either publicly or in private?
  • Do you use your phone a lot throughout the day?
  • Do you stream content regularly - music, movies, podcasts, etc.?
  • Are you a frequent traveller, for work or leisure?
  • Do you always hit your data cap? (Not sure? It’s easy to find out.)
  • Do you find yourself deliberately limiting your data usage?

The more you answer ‘yes’, the more confident we are that an unlimited data SIM is right for you! 

Further information on data usage can be found here:


Is unlimited data actually unlimited?

Mostly, unlimited data is exactly that - unlimited. However, you should check that your plan doesn’t include a fair use caveat, like the one mentioned above. Be sure to double-check for any other warnings and restrictions, too.

Can I use my unlimited data abroad?

Yes, but only if you’re in a ‘Go Roam’ / ‘Roam Like You’re At Home’ destination, as stated on your plan. You may find that countries in Europe have different data caps to the rest of the world! 

With Asda mobile, you can get roaming bundles for 37 popular European destinations, so you never have to worry about going over your data allowance again.

Can I use my phone as a hotspot with unlimited data?

Yes, you can. Set up a hotspot on your phone for other devices (e.g. smartphones, tablets, laptops) to tether off of and access your internet.

Stress-free tethering is only really possible if you opt for unlimited data SIMs, as having multiple devices use your data will see it drop very quickly.

If I don’t use it enough, can I change my unlimited data plan?

This will depend on your network provider’s T&Cs. If you’re locked into a contract, then you may not be able to leave without first paying a fee.

However, at Asda mobile, our short-term bundles only run for 30 days at a time, so if you want to change your plan next month, it’s no big deal!

Unlimited data bundles available with Asda mobile

If you think you’d like to take out an unlimited data SIM plan, we’ve got your ideal selection:

  • Unlimited Value: Great for casual mobile users, and available at just £20 per month, you can listen to music, browse the internet, or surf social media in style.
  • Unlimited Speedy: Great for media consumers, this £22 monthly bundle offers everything from our £20 deal, plus unlimited HD video streaming, stronger download/upload options, and more.
  • Unlimited Superfast: The essential entertainment bundle. Enjoy 4k streaming, online gaming, near-instant downloads, and the rest - all for just £24 a month!

Our plans include variable speed caps, so make sure you choose the right amount of unlimited data for your needs!

Go unlimited from just £20 per month with Asda mobile.

No commitment, no limits
No commitment, no limits

With no commitment you have the freedom to flex your usage whenever you need to.

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Cap your spend
Cap your spend

Put a limit on how much you spend every month so you don't need to worry about getting a big bill.

Never had any problems using data or phone calls. Great price for month to month contract. Purchased another Sim for my son as it’s half the price of our Virgin Media contract.


Solid service, good price. I work abroad but keep my UK number and buy a bundle when I'm back in the country.


I get what I pay for and it all works fine. Now the billing issues from the switch to Vodafone network have been sorted, job's a good 'un.


Very good network cover especially in remote countryside and best date deals and flexibility to change monthly plans.


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